Solid anti-friction devices – materials therefor – lubricant or se – Lubricants or separants for moving solid surfaces and... – Organic oxygen compound
Reexamination Certificate
2000-05-02
2001-09-25
Howard, Jacqueline V. (Department: 1764)
Solid anti-friction devices, materials therefor, lubricant or se
Lubricants or separants for moving solid surfaces and...
Organic oxygen compound
C508S250000, C508S268000, C508S307000, C508S545000, C072S042000
Reexamination Certificate
active
06294508
ABSTRACT:
FIELD OF THE INVENTION
This invention relates to cutting or abrasive working operations, particularly to metal, cermet, or composite cutting or abrasive working operations, and more particularly it relates to cooling and lubricating fluids comprising one or more hydrofluoroether(s) and one or more lubricious additive(s) used in conjunction with such operations.
BACKGROUND OF THE INVENTION
Drilling and machining fluids long have been used in the cutting and abrasive working of metals, cermets, and composites. In such operations, including cutting, milling, drilling, and grinding, the purpose of the fluid is to lubricate, cool, and to remove fines, chips and other particulate waste from the working environment. In addition to cooling and lubricating, these fluids also can serve to prevent welding between a workpiece and tool and can prevent excessively rapid tool wear. See, for example, Jean C. Childers, The Chemistry of Metalworking Fluids, in M
ETAL
-
WORKING
L
UBRICANTS
(Jerry P. Byers ed., 1994).
A fluid ideally suited as a coolant or lubricant for cutting and abrasive working of metal, cermet, and composite materials must have a high degree of lubricity. It must also, however, possess the added advantage of being an efficient cooling medium that is non-persistent in the environment, is non-corrosive (i.e., is chemically inert), and preferably does not leave a substantial residue on either the workpiece or the tool upon which it is used.
Today's state of the art working fluids fall generally into two basic categories. A first class comprises oils and other organic chemicals that are derived principally from petroleum, animal, or plant substances. Such oils commonly are used either straight (i.e., without dilution with water) or are compounded with various polar or chemically active additives (e.g., sulfurized, chlorinated, or phosphated additives). They also are commonly emulsified to form oil-in-water emulsions. Widely used oils and oil-based substances include the following general classes of compounds: saturated and unsaturated aliphatic hydrocarbons such as n-decane, dodecane, turpentine oil, and pine oil; naphthalenic hydrocarbons; and aromatic hydrocarbons such as cymene. While these oils are widely available and are relatively inexpensive, their utility is significantly limited; because they are most often nonvolatile under the working conditions of a drilling or machining operation, they leave residues on tools and work pieces, requiring additional processing at significant cost for residue removal.
A second class of working fluids for the cutting and abrasive working of metals, cermets, or composites includes fluorinated hydrocarbons, such as: chlorofluorocarbons (CFCs), hydrochlorofluorocarbons (HCFCs), and perfluorocarbons (PFCs). Of these three groups of fluids, CFCs are the most useful and are historically the most widely employed. See, e.g., U.S. Pat. No. 3,129,182 (McLean). Typically used CFCs and HCFCs include trichloromonofluoromethane, 1,1,2-trichloro-1,2,2-trifluoroethane, 1,1,2,2-tetrachlorodifluoroethane, tetrachloromonofluoroethane, and trichlorodifluoroethane. The most useful fluids of this second general class of working fluids (CFCs & HCFCs) possess more of the characteristics sought in a cooling fluid, and while they were initially believed to be environmentally benign, they are now known to be damaging to the environment. CFCs and HCFCs are linked to ozone depletion (see, e.g., P. S. Zurer, Looming Ban on Production of CFCs, Halons Spurs Switch to Substitutes, C
HEM.
& E
NG'G
N
EWS,
Nov. 15, 1993, at 12). PFCs tend to persist in the environment (i.e., they are not chemically altered or degraded under ambient environmental conditions).
SUMMARY OF THE INVENTION
Briefly, in one aspect, this invention provides a cooling and lubricating fluid for the cutting and abrasive treatment of metal, cermet, and composite materials wherein the fluid comprises a hydrofluoroether (HFE) and a lubricious additive. The fluid may comprise one or more HFEs and one or more lubricious additives. In another aspect, the present invention provides a method of cutting and abrasively treating metal, cermet, and composite materials comprising applying to the metal, cermet, or composite workpiece and tool a fluid comprising a hydrofluoroether and a lubricious additive.
The fluids used in the cutting and abrasive treatment of metals, cermets, and composites in accordance with this invention provide efficient cooling and lubricating media that fit many of the ideal characteristics sought in a working fluid: efficient lubrication and heat transfer volatility, non-persistency in the environment, and non-corrosivity. The fluids also do not leave a substantial residue (preferably no residue) on either the workpiece or the tool upon which they are used, thereby eliminating otherwise necessary processing to clean the tool and/or workpiece for a substantial cost savings. Because these fluids reduce tool temperature during operation, their use in many cases will also enhance tool life. The addition of lubricious additive increases tool/workpiece lubrication which minimizes the production of heat from friction, further extending tool life and producing better surface finishes on the workpiece.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
The fluids (i.e., liquids) of the present invention may be utilized as cooling and lubricating working fluids in any process involving the cutting or abrasive treatment of any metal, cermet, or composite material (i.e., the workpiece) suitable to such operations. These processes are characterized by the removal of material from the workpiece whose bulk temperature is less than about 80° C., preferably less than about 60° C., during the removal process. Bulk temperature is defined as the average integrated temperature of the workpiece. The most common, representative, processes involving the cutting, separation, or abrasive machining of workpieces include drilling, cutting, punching, milling, turning, boring, planing, broaching, reaming, sawing, polishing, grinding, tapping, trepanning and the like.
Metals commonly subjected to cutting and abrasive working include: refractory metals such as tantalum, niobium, molybdenum, vanadium, tungsten, hafnium, rhenium, and titanium; precious metals such as silver, gold, and platinum; high temperature metals such as nickel, titanium alloys, and nickel chromes; and other metals including magnesium, copper, aluminum, steel (including stainless steels), and other alloys such as brass, and bronze. The use of the fluids of the present invention in such operations acts to cool the machining environment (i.e., the surface interface between a workpiece and a machining tool) by removing heat and particulate matter therefrom. These fluids will also lubricate machining surfaces, resulting in a smooth and substantially residue-free machined workpiece surface.
Cermets are defined as a semisynthetic-product consisting of a mixture of ceramic and metallic components having physical properties not found solely in either one alone. Examples include, but are not limited to, metal carbides, oxides, and suicides. See Hawley's Condensed Chemical Dictionary, 12
th
Edition, Van Nostrand Reinhold Company, 1993.
Composites are described herein as laminates of high temperature fibers in a polymer matrix, for example, glass fiber in an epoxy resin. Neat hydrofluoroethers may be used as a coolant and lubricant for composites. However, lubricious additives may provide for increased drill speed for composites.
The cooling and lubricating fluids of this invention comprise hydrofluoroethers that may be represented generally by the formula:
(R
1
—O)
n
—R
2
(I)
where, in reference to Formula I, n is a number from 1 to 3 inclusive and R
1
and R
2
are the same or are different from one another and are selected from the group consisting of alkyl, aryl, and alkylaryl groups. At least one of R
1
and R
2
contains at least one fluorine atom, and at least one of R
1
and R
2
contains at least one hydrogen atom. Optionall
Grenfell Mark W.
Milbrath Dean S.
3M Innovative Properties Company
Fagan Lisa M.
Howard Jacqueline V.
LandOfFree
Composition comprising lubricious additive for cutting or... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Composition comprising lubricious additive for cutting or..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Composition comprising lubricious additive for cutting or... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2509159